Lilaoshia psorospermi Burckhardt, Aléné and Serbina, 2025

Aléné, Désirée C., Serbina, Liliya Š., Djiéto-Lordon, Champlain, Malenovský, Igor & Burckhardt, Daniel, 2025, Unusual feeding behaviour and association with ants in Lilaoshia psorospermi sp. n. (Hemiptera: Psylloidea: Liviidae) developing on Psorospermum glaberrimum (Hypericaceae), Journal of Natural History 59 (9 - 12), pp. 573-586 : 576-582

Lilaoshia psorospermi Burckhardt, Aléné and Serbina sp. n.

( Figures 2–5 )

LSID urn:lsid:zoobank.org:act:641CC179-FAA7-4BD4-9F54-B6813D8802D1

Liella cf. insolita (Mifsud and Burckhardt) , Burckhardt et al. (2023)

Type material

Holotype male, CAMEROON: West Region, Department of Noun, vicinity of Koutaba, near Tchouffa village , 5.6702°N, 10.7884°E, 1230 m, 28 October 2017, Psorospermum glaberrimum (D.C. Aléné) #PF8 ( NHMB, dry mounted). – Paratypes. CAMEROON: 3 males, 19 females, 158 immatures, 3 skins, same collecting data as for holotype ( MMBC, NHMB, dry- and slide-mounted or conserved in 70% ethanol) .

Additional specimens from the same locality as the holotype were observed in the field. They are not part of the type series.

Diagnosis

Adult

Antenna 0.8–0.9 times as long as head width; rhinaria lacking associated bifid setae; antennal segment 9 with one long seta. Forewing irregularly rounded apically; surface spinules densely spaced, covering all cells up to the veins; radular spinules absent. Abdomen lacking horn-like dorsal structures; tergites with a row of simple setae laterally. Paramere without peg-like setae on the inner face. – Fifth-instar immature. Body elongate. Antenna 3-segmented, lacking sectasetae. Forewing pad bearing 3–5 pointed marginal sectasetae. Sectasetae on abdominal margin based upon small but not extended tubercles. Caudal plate truncate.

Description

Adult

Colouration. Mostly dark brown. Head greyish brown dorsally, light brown ventrally; ocelli reddish; eyes reddish or purple. Antenna yellowish, apex of segments 8, 9 and 10 almost black. Clypeus light brown; rostrum yellowish with black tip. Thorax irregularly dark brown or almost black with some yellow areas laterally. Legs yellow with brown tarsi; metacoxa and metafemur partially brown. Forewing subopaque, greyish with dark brown spots at the base and apex of pterostigma, in the middle of veins R + M+ Cu, R and M+ Cu, at the basal quarter of Rs, on the apices of veins Rs, M1+2, M3+4, Cu1a and Cu1b, and at the base and in the middle of A; with indistinct brown infuscation in cell cu2, a more distinct light brown irregular band stretching from the base cell r2 to the apex of vein Cu1b, and an oblique light brown submarginal band stretching between the apices of veins Rs and Cu1a. Hindwing semitransparent, whitish. Abdominal sclerites dark reddish brown, intersegmental membranes yellowish. Younger specimens with more extended light colour.

Structure

Conforming to generic description by Burckhardt et al. (2023) (see also Mifsud and Burckhardt (2002) under the Paurocephala gossypii group). Head weakly (10–20°) inclined from longitudinal body axis ( Figure 2 (a)); slightly narrower than mesoscutum; vertex subrectangular, 0.5-times as long as wide, covered with short setae and imbricate microsculpture ( Figure 2 (b)). Antenna ( Figure 2 (b)) 0.8–0.9-times as long as head width, 10-segmented; rhinaria lacking associated bifid setae; antennal segment 9 with one long seta, relative lengths of segment 10 and terminal setae 1.0:1.8:2.3 ( Figure 2 (c)).Clypeus subglobular,with 3 apical, moderately long setae; rostrum 0.5-times as long as head width ( Figure 2 (d)). Thorax covered with short setae and imbricate microsculpture.Horn of metapostnotum small.Meracanthus of metacoxa short, horn-shaped;metatibia 0.8–0.9 times as long as head width ( Figure 2 (f)).Forewing ( Figure 2 (g)) 2.7–2.9-times as long as head width, 2.1–2.3-times as long as wide; irregularly, obliquely rounded apically; setae along veins inconspicuous, sparse, vein Rs with 9–14 setae; surface spinules densely spaced covering all cells up to the veins ( Figure 2 (h)); radular spinules absent ( Figure 2 (i)).Abdominal tergites lacking a dorsal horn, bearing one row of simple setae laterally. Male and female terminalia as in Figure 3 . Male proctiger 0.2–0.3-times as long as head width, with weakly sclerotised, elongate plates posteriorly. Paramere, in lateral view, lamellar in basal half, irregularly narrowing to apex in apical half; apex subacute; without peg-like setae on the inner face.Apical dilation of aedeagus oval,flattened,divided by a cuticular fold from the stemlike basal part of the distal aedeagal segment; sclerotised end tube of ductus ejaculatorius almost straight. Female proctiger 0.9–1.1-times as long as head width, cuneate; dorsal margin, in lateral view, slightly concave with indistinct swelling in the middle; apex subacute; circumanal ring 0.3-times as long as proctiger, consisting of two unequal rows of pores. Female subgenital plate 0.2–0.4-times as long as proctiger, pointed apically. Valvula dorsalis cuneate; valvula ventralis straight; both lacking teeth.

Measurements (inmm; body length: 2 males, 12 females; other characters: 2 males, 2 females).

Body length males 2.2–2.3, females 2.3–2.6; head width 0.60–0.64; antenna length 0.50–0.58; forewing length 1.66–1.80; male proctiger length 0.12–0.16; paramere length 0.20; length of distal segment of aedeagus 0.16; female proctiger length 0.60–0.64.

Fifth-instar immature

Colouration. Dorsal sclerites mostly light brown, membrane yellowish; whitish ventrally. Cephalothoracic sclerite light brownish anteriorly and laterally, brown posteriorly, yellow on disc; wing pads yellow with broad brown margin.

Structure

Body elongate, 1.2–1.3-times as long as wide, dorso-ventrally flattened ( Figure 4 (a)). Antenna 3-segmented, 0.6–0.8-times as long as forewing pad, bearing some simple setae on flagellum but lacking sectasetae ( Figure 4 (b)). Tarsal arolium triangular, petiolate, bearing an unguitractor ( Figure 4 (c)). Forewing pad lacking humeral lobe, bearing 3–5 pointed marginal sectasetae. Sectasetae on abdominal margin based upon small but not extended tubercles ( Figure 4 (a,d)). Caudal plate ( Figure 4 (d)) truncate. Circumanal rings in terminal position; outer ring transversely oval, consisting of a single row of pores.

Measurements (in mm; 4 specimens)

Body length 1.38–1.50; antenna length 0.32–0.42; metatibiotarsus length 0.43–0.45; forewing pad length 0.53–0.56; caudal plate length 0.30–0.38; caudal plate width 0.43–0.48.

Egg.

Colouration. Whitish when laid, yellow when mature.

Structure

Narrowly oval; laid in dense clusters on the leaf surface ( Figure 5 (b)).

DNA sequence data

Burckhardt et al. (2023) used specimens of Lilaoshia psorospermi in their phylogenetic analysis of the Liviinae (referred to as ‘ Liella cf. insolita ’). They provided some additional illustrations of morphological characters and DNA sequences for six genes: COI (GenBank accession number MW119598 ), CytB ( MW119632 ), H3 ( MW119667 ), wg ( MW119700 ), 12S ( MW218185 ), 28S ( MW218415 ).

Host plant

Psorospermum glaberrimum Hochr. ( Hypericaceae ).

Distribution

Cameroon: West Region.

Etymology

Named after its host plant Psorospermum .

Comments

Lilaoshia psorospermi is morphologically similar to L. insolita from Angola, which develops on Psorospermum febrifugum Spach ( Mifsud and Burckhardt 2002). The two species share the abdominal tergites without dorsal horns, but with a row of setae laterally; both lack bifid setae associated with the antennal rhinaria and peg-like setae on the inner side of the paramere. Lilaoshia psorospermi differs from L. insolita in the generally darker body colouration, the presence of a long seta on antennal segment 9, the slightly shorter meracanthus, the paramere which is not narrowed in the basal half and the oval terminal aedeagal segment in the adult, as well as in the absence of sectasetae on the antenna, the smaller number of marginal sectasetae on the forewing pad (3–5 versus 5–7), the smaller lateral abdominal tubercles bearing sectasetae, and the truncate caudal plate (rather than produced in a terminal process) in the fifth-instar immature. The two species differ also in the host association: Psorospermum glaberrimum versus P. febrifugum .

Biology

Adult and immature Lilaoshia psorospermi were observed together with the following four ant species ( Hymenoptera , Formicidae ): Camponotus congolensis Emery , C. flavomarginatus Mayr , Crematogaster striatulus Emery and Tapinoma sp. With 561 individuals observed, C. striatulus was the most abundant ant species followed by the two Camponotus species (431 individuals) and Tapinoma sp. (10 individuals). Immatures of L. psorospermi fed on the lower leaf surface, near the midrib or on the proximal leaf margin near the petiole. Feeding led to leaf depigmentation and leaf drop.

Population levels of psyllid infestations and their accompanying ants varied significantly between leaf-age classes of P. glaberrimum . The highest number of psyllids was found on the old leaves (47%), decreasing on the young leaves (32%) and very young leaves (21%). For the ants, the pattern was roughly the same, with significant differences confirmed by the Kruskal– Wallis test ( Table 1 ).

The Spearman correlation test performed between the numbers of individuals of C. striatulus and L. psorospermi showed a positive significant correlation (R = 0.33; p =.002). In contrast, Camponotus spp. and Tapinoma sp. showed no significant correlation with L. psorospermi (R = 0.02, p =.87 and R = 0.13, p =.25, respectively). The following two ant taxa associated with L. psorospermi always built shelters around and above the psyllid colonies. The shelter built by Camponotus spp. consisted of soil ( Figure 5 (c)), while that by Crematogaster striatulus was made of soil or sand mixed with plant debris ( Figure 5 (e, f, g)). For Tapinoma sp. the building of a shelter was not mandatory. These ants were among the colonies to feed on the honeydew excreted by the psyllids.

Figures

Figure 2. Lilaoshia psorospermi Burckhardt, Aléné and Serbina sp. n.: (a) habitus, lateral view (reproduced from Burckhardt et al. 2023, by permission of the Linnean Society of London and Oxford University Press); (b) head with antennae, dorsal view; (c) apex of antenna with setae; (d) clypeus and rostrum, lateral view; (f) hind leg, lateral view; (g) forewing; (h) surface spinules in cell r1 anterior to bifurcation of M; (i) surface spinules in cell r1 near wing margin.

Figure 3. Lilaoshia psorospermi Burckhardt, Aléné and Serbina sp. n., terminalia: (a) male terminalia, lateral view; (b) inner face of paramere, lateral view; (c) apex of proximal segment and distal two segments of aedeagus, lateral view; (d) female terminalia, lateral view. Scale bars = 0.1 mm.

Figure 4. Lilaoshia psorospermi Burckhardt, Aléné and Serbina sp. n., fifth-instar immature: (a) habitus, dorsal view (left side); (b) antenna; (c) claws and tarsal arolium; (d) caudal plate, dorsal view (right side).

Figure 5. Lilaoshia psorospermi Burckhardt, Aléné and Serbina sp. n., biology: (a) Crematogaster striatulus ants tending adult and immature psyllids; (b) eggs, parasitised mummies and dead adult; (c) Camponotus ants construct a shelter around a female psyllid laying eggs; (d) old leaf with colony of adult and immature psyllids tended by Tapinoma ants; (e) psyllid colony with adult, immatures and eggs tended by Crematogaster striatulus ants after removing the cover; (f) cover over a psyllid colony built by C. striatulus ants; (g) shelter consisting of sand and plant debris built by C. striatulus.